scholarly journals Variable Porosity of the Pipeline Embolization Device in Straight and Curved Vessels: A Guide for Optimal Deployment Strategy

2013 ◽  
Vol 35 (4) ◽  
pp. 727-733 ◽  
Author(s):  
M. Shapiro ◽  
E. Raz ◽  
T. Becske ◽  
P. K. Nelson
2008 ◽  
Vol 57 (1-6) ◽  
pp. 119-127 ◽  
Author(s):  
D. Danusevičius ◽  
D. Lindgren

Abstract This study deals with how the deployed proportion of each candidate clone can be decided at the establishment of a seed orchard when the breeding values are available for each candidate in a population of unrelated half-sib families. The following deployment strategies were compared: (a) truncation selection by selecting the clones with the breeding values exceeding certain threshold and deploying equal number of ramets (Truncation strategy); (b) truncation selection by selecting only one best individual within each family (Truncation unrelated); (c) maximizing gain at a given effective clone number (Linear deployment); (d) linear deployment by selecting one best individual within each family (Linear deployment unrelated) and (e) maximizing net gain at a given gene diversity (Optimal proportions). The study focused on the latest alternative and described its superiority and characteristics for a number of possible typical cases. The genetic gain adjusted for predicted inbreeding depression (Net gain), gene diversity and effective clone number were considered as the main ranking criteria. The strategies optimizing the number of related individuals and the linear deployment strategy with restriction on relatedness returned the highest Net gain. If there is a large diversity to select from (the status number of the candidates is more than 8 times greater than the status number desired in the seed orchard), a relatively simple advice is to select the best individual within the best families and deploy the clones linearly according to their breeding values (the number of families selected depends on the desired status number). If the diversity available to select from is small, it seems recommendable to allow half-sibs among the selections and use the Optimal proportions deployment strategy. As the breeding cycles proceed, the status number of the candidate population will decrease and the Optimal proportions strategy is likely to become more favorable.


2014 ◽  
Vol 02 (04) ◽  
pp. 377-389 ◽  
Author(s):  
Suruz Miah ◽  
Bao Nguyen ◽  
François-Alex Bourque ◽  
Davide Spinello

We propose a nonuniform deployment strategy of a group of homogeneous autonomous agents in harbor-like environments. High value units berthed in the area need to be secured against external attacks. Defenders deployed in the area are expected to monitor, intercept, engage, and neutralize threats. In the framework of decentralized coordinated multi-agent systems, we model and simulate the optimal deployment of a group of mobile autonomous agents that accounts for a risk map of the area and the optimal trajectories that minimize the energy consumed to intercept a threat in a given area of interest. Theoretical results are numerically illustrated through simulations in a realistic harbor protection scenario.


2018 ◽  
Vol 7 (2.21) ◽  
pp. 161
Author(s):  
Jeane Marina D’Souza ◽  
Siddhartha Suresh Rao ◽  
K R. Guruprasad

In this paper we address a problem of optimal deployment of camera mounted UAVs for a multi-robot search application. Here   multiple UAVs carrying downward facing cameras are required to look for targets of interest in a search area. The lack of information about the presence or absence of targets is modeled as an uncertainty density distribution over the search area and this uncertainty is reduced as the information is gathered using the onboard cameras. The UAVs are required to get deployed so as to maximize the uncertainty reduction. We provide a model for search effectiveness of the camera and use it to formulate a strategy for optimal deployment of UAVs. It is shown that a centroidal Voronoi configuration, where each UAV (camera) is located at the centroid of the corresponding Voronoi cell is an optimal deployment. We provide simulation results to demonstrate that the proposed optimal deployment strategy successfully      deploys the UAVs into centroidal Voronoi configuration, which maximizes the uncertainty reduction using cameras as search sensors.  


2019 ◽  
Vol 17 (5) ◽  
pp. 491-496 ◽  
Author(s):  
Edgar A Samaniego ◽  
Sudeepta Dandapat ◽  
Jorge A Roa ◽  
Mario Zanaty ◽  
Daichi Nakagawa ◽  
...  

Abstract BACKGROUND Embolization of intracranial aneurysms with the pipeline embolization device (PED; Medtronic, Dublin, Ireland) is a widely used technique. Despite adequate dual antiplatelet therapy and intraprocedural anticoagulation, in-stent thrombosis has been described. There is limited evidence for best management of this complication. OBJECTIVE To describe in detail the technique used to perform thrombectomy of a recently placed PED with in-stent thrombosis. The aim of the procedure is to leave the PED in place and only perform thrombectomy of the luminal clot. METHODS We describe two cases of successful thrombectomy with a stentriever of acutely occluded PEDs. A total of 2 patients underwent PED embolization of 2 previously clipped aneurysms. Despite optimal deployment of the PEDs and excellent angiographic results, both patients developed symptoms of right hemispheric stroke within 1 h of the procedure. A thrombectomy was performed in each patient with the stentriever within the newly deployed PED. Thrombectomy was successful and there was no evidence of PED displacement of vascular injury. RESULTS Stentriever thrombectomy of intraluminal clot can be performed effectively when the entire stentriever device is deployed within the PED. We did not experience any PED displacement, vessel damage, spasm, or device malfunction using this technique. CONCLUSION We report the use of a stentriever to perform thrombectomy for in-stent thrombosis after PED placement as an additional treatment option of acute occlusion. This technique has not been previously described.


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